Finagle support for tracing and metrics

[greggdonovan]

Finagle is a popular JVM RPC system used at Twitter, FourSquare, Tumblr, Etsy, etc. Finagle is written in Scala, but provides both Scala and Java idiomatic APIs.

Finagle has existing tracing support for Zipkin and exposes a large amount of metrics.

[Sebruck]

Could be either part of Finagle itself or part of https://github.com/Sebruck/opencensus-scala , we already have instrumentations for akka-http and http4s there.

[codefromthecrypt]

historically speaking, it is likely best to get some of the core finaglers in on this as they'll have more stake in how things go. zipkin for example, it actually not zipkin as much as finagle's internal tracing library. For example, finagle's tracing library is not used by anything but finagle, and it isn't directly linked to zipkin either.

Probably you could make a project like zipkin-finagle https://github.com/openzipkin/zipkin-finagle which uses census instead as a start as it is a lot less work than ripping all of the internal infrastructure out for something else. Finagle is managed as a monorepo, so basically it is a fairly big effort to track instrumentation directly... doing a finagle tracer impl is a lot lower hanging fruit.

[semistrict]

Should this issue be moved to the opencensus-java?

[songy23]

This is for both Scala and Java, I think it makes more sense to keep it in this repo.

[LiuVII]

Hey guys! Wonder is there an update on this?

[pjanotti]

@LiuVII not sure if it is an option in your case, but one possibility is to use the OC Agent/Collector receiving zipkin and exporting in the format that you need.

[codefromthecrypt]

or trace exporter even. I don't think agent would be required. This would work for the few options census has but there are no direct zipkin reporters for.